Power unit for cranes



Dec. 16, 1947. -H. B. HAYES POWER UNIT FOR CRANES Filed June 14, 1945 INVENTOR. /7694 /3. H0 YES.

.easily and directly by the operator.

Patented Dec. 16, 1947 POWER UNIT FOR CRANES Hal B. Hayes, Tujunga, Calif., assignor to Hayes Econocrete Corporation of America, Reno, Nev., a corporation of Nevada Application June 14, 1945, Serial No. 599,364

4 Claims.

This invention relates to hoisting apparatus, and particularly pertains to a power unit for cranes, V

In the type of crane shown in U. S. Letters Patent No. 2,370,661, entitled Portable cranes, and issued to me on March 6, 1945, I have shown a crane which embodies means for raising and lowering the crane boom, for raising and lowering the load, and rotating the boom mounting around a horizontal axis. It is desirable to provide a cheap and simple power unit for performing the aforesaid operations, and which Lmit is so constructed as to be manipulated It is also desirable to provide a power unit of the character described in which the driving element is normally in constant driving engagement with the various driven units, and in which driving force may be easily interrupted without the use of positive clutch means. This makes it possible to perform the various operations without violent movement or undue strain upon the parts. It is also desirable to provide a power unit for use on hoists and the like which may be made from salvaged used parts so that a conservation of material and labor is eifected. It is the principal object of the present invention, therefore, to provide a power unit for portable cranes and the like, which comprises a prime mover with which transmission and differential units may be connected in a manner to impart driving force to various driven elements in a simple and direct way, and which transmission and differential units may be salvaged parts from automobiles and trucks.

The present invention contemplates the provision of a power unit fitted with a clutch and transmission, the said transmission driving a pair of differential gear units in series, the gear units being designed to impart driving force to various driven members.

The invention is illustrated by way of example in the accompanying drawings in which:

Figure 1 is a view in side elevation showing the application of the power unit embodying the present invention as installed in a crane.

Fig. 2 is an enlarged view in vertical section showing the details of the power unit.

Fig. 3 is a view in horizontal section showing the gear reduction drive for the turntable.

Fig. 4 is a view in vertical section as seen on the line 4-4 of Fig. 1 showing certain of the control levers.

Referring more particularly to the drawings,

I indicates the main frame of a. crane, which 2 is here shown as being mounted upon a truck. although it is understood that the present invention is not concerned with its portability or the crane construction. A turntable base I! is mounted on the frame and carries a circumferential trackway l2. Rollers l3 and I4 engage opposite sides of this trackway and are mounted upon a turntable 15. The turntable l5 rotates around the vertical axis of a king pin l6 carried by the base I I. The turntable as here shown is formed with a balancing arm I1 carrying a weight [8 which is disposed upon the opposite side of the turntable from that upon which the boom I9 is mounted. The boom I 9 is raised and lowered by a cable 20. Led over a suitable pulley on the boom is a cable 2| which raises and lowers the load. The turntable is intended to rotate around its ver tical axis as driven by means hereinafter explained, it being understood that the turntable drive and the drive for the two cables 20 and 2| all receive their driving force from a prime mover, such as the engine 22. The engine 22 is mounted upon the turntable frame and is in driving connection with the usual disc clutch 23. The disc clutch is here shown as fitted with an operating lever 24. .This lever supplants the usual foot lever with which a driving clutch is connected. A shaft 25 con nects the clutch 23 with a variable speed transmission 26 of the conventional type used in automobiles. This transmission is equipped with gearing to provide a plurality of speeds, ahead and a reverse speed; The transmission is equipped with a gear shift lever by which the selected speed and driving direction may be established. A shaft 28 connects the transmission 26 with a differential gear unit 29. The differential gear unit 29 is of the conventional type used in automobile rear axles. In this particular case an automobile rear axle has been selected and the opposite tubular extension-s of the housing have been cut away so that the housing portion 30 is provided to em close the differential gear unit only, and to furnish bearing support for longitudinally aligned shafts 3| and 32. The shafts 3| and 32 are vertically disposed and are at right angles to the shaft 28, which extends horizontally. It will be understood that the differential gear unit enclosed within the housing 30 is capable of imparting simultaneous rotation to the shafts 3| and 32 in the same direction or travel.

Mounted upon the shaft 3| is a brake drum 33 fitted with a suitable brake band 34 connected with a brake operating mechanism 35 by which the band may be caused to grip the drum or to release it. The lower extension of the shaft 3| carries a driving sprocket 36 around which a sprocket chain 31 is led. This chain passes around a large sprocket wheel 38 carried by the turntable I and is disposed concentric with the kingpin I6, It will be seen that this driving arrangement gives a suitable gear re duction and allows the turntable to revolve slowly upon its vertical axis. It should be explained that the brake actuating structure 35 is held normally in its setposition by a spring 39 which prevents rotation of the shaf-t3l.

The shaft 32 connects through a universal joint 32' with a differential gear. unit 40,- which is disposedabove and at right angles to the longitudinal axis of the shaft 32. This gear unit may also be a differential gear structure alvaged from an automobile rear axle. It carries shafts 4| and 42'. cable drum 43 around which the end of the boom lift cable 2| is wound. The shaft 42 carries a cable drum 44 around which the load: lift cable 20 is wound. Mounted at the outer end of the shaft 4| is. a brake drum 45 fitted with a brake band 46. This is actuated by brake mechanism 4! which will permit the brake to be held against rotation or released. A spring 48 acts to hold the brake band 46 normally in a set position to prevent rotation of the brake drum and the shaft 4|. Mounted on the outer end of the shaft 42. is a brake drum 49 carrying a brake band 5|]; This band is operated by a brake operating mechanism 5| held normally in a set position by a spring 52.

. The brake operating mechanisms 35, 41 and 5| are provided with connecting rods or cables 53, 54 and 55, respectively. These cable's lead to operating levers 56, 51 and 58, respectively. The

lever 56 is fixed upon a shaft 59 rotatably sup-- ported in bearings 65 and 6|, and disposed in a convenient horizontal position transversely of the operators seat '62, shown in Fig. 1 of the draw ing. An operating lever .63'is'fixed upon the shaft 59 and maybe manipulated by the operator. hasbeen previously explained, the spring 39 acts to hold the brake band34- in a set position upon the drum 33.

A sleeve 64 is rotatably mounted upon the shaft 59 andcarries the lever arm 5'5. An operating lever 65 is also fastened to this sleeve so-that it may be manually rotated. The spring 48 acts to hold this-mechanism so that the brake drum 46iis normally-set. Rotatably mounted uponthe sleeve 64 is a sleeve 66. This sleeve carries the lever 58 to which the cable 55 is connected; The

sleeve 66 also carries an operating lever 61 by manipulation of which the brake operatingmechanism 5| may be actuated. The spring 52 nor' mally holds the brake drum 53 in its'set position. It will thus be seen thatbymanipulation of the operating lever 63 the turntable brake drum 34 may be released that by manipulation of operating lever 65' the boom lift drum45 may beres leased, and that by operation of lever 61 the load lift, drum 49 may be released. The releasing action is brought about against the tension of the springs 39, 45 and 5.2;

In operation of the present invention, the. structure is assembled as shownxparticularly in- Figs. I and.2 of thedrawin'g. It is to beunderstood that the invention is particularly concerned withthe. power transmissionrunit' by which: power The shaft 4| serves as a mounting for a 4 may be selectively delivered to the turntable l5, the boom cable drum 43, and the load cable drum 44, and that driving force may be imparted to one or more of said units simultaneously. This unit includes two differential gear sets. These gear sets may be embodied in a structure particularly designed for the present purpose or may be constructed from salvaged used automobile axles, as previously cited. In any event, the assembled structure is arranged as indicated in detail in Fig. 2 of the drawing, where the prime -mover 2-2 is directly connected with the clutch tiple speed transmission 26.

23 which rotates the shaft 25 leading to a mul- Power is then delivere'd" through the shaft 28 to the first differential unit 29. When the transmission is in neushafts 3|, 4|, and 42 the gear shift lever 21 is shifted to a desired speed while the clutch lever 24 is manipulated to throw out the clutch. As the'clutch is set a driving action is set up through the'transmission 26 through the drive shaft 22. At this time'the operator manipulates one or more of the control levers 63, 65 or 61. It will be seen that by release of the brake which is associated with these levers that the particular instrumentality normally held idle by the brake will be driven. Thus, if lever 63 is operated it will release the brake band 34 and allow the turntable to be driven through the sprocket 35, the sprocket chain 31, and the large turntable sprocket 38. In the event it is desired to drive either of the cable drums 43- or 44 the brake lever 65 or 61 may be manipulated. The driving action will all take place through one clutch, and an overload on any one of the instrumentalities will cause the slippage of the clutch. When any one of the operating levers 63, 65 or 61 is released the respective springs 39, 48 and 52 will act through the brake setting mechanisms to set the brake and to hold the brake drums against rotation. It will also be seen that the individual units may be driven quite flexibly due to the control of their respective brakes, and that it is not necessary to shift any gears after the structure is placed in operation but merely to control the different brake units. This gives a flexible control for each drive without throwingv any excessive load upon the structure. The present construction also obviates the use of separate drive take-off shifts for each of the in'strumentalities being driven, and separate clutches and speed changing transmissions for them.

It should be pointed out that under normal conditions the brake springs hold the brakes set, and that driving is effected in. any one of the driving sections of the unit when that particular brake is released. Due to this arrangement the various operations may be changed selectively withoutany manipulation of the clutch. When it is desired to release a load on either of the drums the brake is released and the clutch is thrown out. This will allow the load to be placed on the driving'unit Has the drums rotate in a direction to unwind the cable. It is also-obvious that the load may be set down when the transmission is in neutral. Due to this arrangement the structure may be controlled accurately and by the manipulation of a minimum number of control devices.

It will thus be seen that by the power unit construction here disclosed it is possible to provide one prime mover through which a plurality of separate instrumentalities may be driven as controlled by one clutch, and to additionally pro vide individual controls which operate on the friction brake principle, the structure being inexpensive in construction and easy to operate.

While I have shown the preferred form of my invention as now known to me, it will be understood that various changes may be made in combination, construction and arrangement of parts by those skilled in the art, without departing from the spirit of the invention as claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A power transmission unit, comprising a clutch structure adapted to be driven from a prime mover, variable speed transmission driven by the clutch structure, a differential unit driven by the transmission, a pair of longitudinally aligned shafts in constant connection with and being separately driven by the differential unit, a second differential unit driven by one of said aligned shafts, said second differential unit carrying a pair of longitudinally aligned shafts separately driven thereby, three brake drums, one fixed upon each of said last named shafts and the other fixed upon the remaining shaft of the first differential unit, separate brake operating mechanisms associated with each of said brake drums and normally holding the brake drums in a set position, selective means for releasing the several brake drum operating mechanisms, and separate instrumentalities positively connected to the various brake carrying shafts.

2. A power driven crane, in which structure a boom is mounted for vertical swinging movement, its base being mounted for rotation around a vertical axis and a hoisting cable being carried by the boom, which power unit includes a friction clutch to be driven from a prime mover, a variable speed transmission in driving connection with the clutch, a first differential gear unit driven from the transmission, a pair of separate shafts disposed in longitudinal alignment and being separately driven by said first differential gear unit, one of said shafts being a connecting shaft and the other being a turntabl drive shaft, a second differential gear unit driven from the connecting shaft, a pair of drive shafts longitudinally aligned and separately driven from the second differential gear unit, one of said shafts being a boom cable drum drive shaft, and the other of said shafts being a load cable drum drive shaft, brake drums, one fixed upon each of said drive shafts, separate braking mechanisms, one associated with each of said brake drums and normally set to hold a brake against rotation, and control levers, one for each of said braking mechanisms, whereby the brake drums may be separately or simultaneously released.

3. A power driven crane which includes a turntable, a boom cable, and a load cable; said power unit comprising a prime mover, a friction clutch driven therefrom and controllable by an operating lever, a, variable speed transmission driven from the clutch and controllable by an operating lever, a horizontal shaft driven by said transmission, a differential gear set driven by said horizontal shaft, vertically aligned shafts driven by the differential gear set, one shaft extending downwardly and th other shaft extending upwardly, a turntable drive sprocket carried by the lowermost of said shafts, a turntable sprocket of relatively large diameter, a chain leading around both of said sprockets for imparting driving motion from one to the other, a brak drum carried by said downwardly extending shaft, brake setting means associated therewith and yieldably held normally in a set position, an upper differential gear above said first named differential gear, said gears being in driving connection through the upwardly extending shaft of the first named differential, a pair of shafts in horizontal and longitudinal alignment at the opposite sides of the upper differential gear set and driven separately therefrom, a boom cable winding drum carried by one of said shafts, a brake drum mounted upon said shaft, brake setting means associated with said drum and normally acting to hold the drum against rotation, a load cable winding drum mounted on the other of said shafts, a brake drum associated therewith, brake setting means normally acting to hold said brake against rotation, and a set of control levers disposed conveniently adjacent to the clutch and transmission levers for separately releasing the individual brake setting means.

4. A power transmission unit comprising a friction clutch driven from a prime mover, a variable speed transmission driven by the friction clutch, a power output shaft driven by said transmission, a differential gear unit driven by the power output shaft, a pair of longitudinally aligned drive shafts at the opposite sides of said gear unit and diiferentially driven thereby, a brake structure associated with one of said drive shafts and being normally set to hold said shaft against rotation, a second differential unit driven by the remaining longitudinally aligned shaft associated with the first differential unit, a pair of longitudinally aligned driven shafts associated with the second differential gear unit, a pair of brake structures one for each of said last named aligned shafts, said structures being held normally in a set position, and driving means associated with each of the shafts carrying a brake mechanism whereby when the brake upon said shaft is released th shaft may freely rotate.

HAL B. HAYES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 723,731 Reise Mar. 24, 1903 1,374,947 Newhouse Apr. 19, 1921 1,755,909 Bernard Apr. 22, 1930 1,769,991 Fundom July 8, 1930 2,370,661 Hayes Mar. 6, 1945 

